Energy absorption behavior of foam-filled sandwich composite materials reinforced by lattice webs under quasi-static compression

Composite sandwich structure has higher specific strength, specific stiffness, excellent corrosion resistance, good fatigue resistance and simple molding process, etc. Composite sandwich specimens were produced with face sheets and lattice webs which were made from glass fiber reinforced polymer (GFRP) and core made from polyurethane (PU) foam. The vertical lattice webs were transformed into double-layered orthogonal lattice webs, double-layered dislocation lattice webs and triple-layered dislocation lattice webs. Quasi-static compression experiment was performed on specimens to compare their failure modes and performance of energy absorption. The results show that the triple-layered dislocation lattice webs have ideal load-displacement curves. After changing the spatial position of the lattice webs, the elastic decline is extended, and the bearing capacity of the specimen is improved. Compared with the vertical lattice webs, the energy absorption value of the triple-layered dislocation lattice webs increases by 91.9%. The equivalent cross model was assumed to calculate the equivalent elastic compression stiffness of the double-layered orthogonal lattice webs, and the elastic stiffness of the double-layered orthogonal lattice webs is greatly affected by the lattice compression modulus. Numerical simulations using ANSYS/LS-DYNA were conducted on composite panels. By comparing the material properties and failure modes obtained from the experimental investigations, the accuracy of the numerical simulation could be well predicted, and the energy absorption of the GFRP webs and foam was compared and analyzed by numerical simulation.